It partly depends on how small your target group is. If you want to reach "People who travel" then targeting the travel page of the NYT should work nicely. But

It partly depends on how small your target group is. If you want to reach "People who travel" then targeting the travel page of the NYT should work nicely. But to play devil's advocate, what if you want to reach the 300 oncologists who prescribe your competitor's drug for Specific Rare Cancer and not your drug? Advertising in the cancer journals might be too expensive for your niche brand and you might want to run different messages to different groups within the 300.